I did a little digging. It looks like IOException is thrown when the other
side closes its connection while we're waiting on our buffer to fill up. We
totally expect that in this test. It feels to me like we should throw a
`ConnectionClosedException` but upstream does not agree:
https://issues.apache.org/jira/browse/HTTPASYNC-134
While we *could* catch the exception and transform it ourselves that
seems like a bigger change than is merited at this point.
Closes#29136
I have long wanted an actual test that dying with dignity works. It is
tricky because if dying with dignity works, it means the test JVM dies
which is usually an abnormal condition. And anyway, how does one force a
fatal error to be thrown. I was motivated to investigate this again by
the fact that I missed a backport to one branch leading to an issue
where Elasticsearch would not successfully die with dignity. And now we
have a solution: we install a plugin that throws an out of memory error
when it receives a request. We hack the standalone test infrastructure
to prevent this from failing the test. To do this, we bypass the
security manager and remove the PID file for the node; this tricks the
test infrastructure into thinking that it does not need to stop the
node. We also bypass seccomp so that we can fork jps to make sure that
Elasticsearch really died. And to be extra paranoid, we parse the logs
of the dead Elasticsearch process to make sure it died with
dignity. Never forget.